We all know that ocean plastic is a major problem, but recent statistics point to just five Asian countries as responsible for between 55 and 60 percent of the plastic that finds its way to the oceans: China, Indonesia, Vietnam, Thailand and the Philippines.

An estimated 8 million tons of plastic end up in the world’s oceans each year, from garbage finding its way into the oceans through waterways, to flotsam and jetsam from ships, to plastic microbeads in cosmetics, such as the ones that were recently banned in California. All of this material threatens the marine environment, both directly when animals try to eat it and choke on it, and indirectly by toxins, which are released as the plastic decays and which poison the environment and its animals.

While numerous suggestions have been made as to how to clean up the plastic, it is unlikely that any of these will be a match for the flow of new plastic each year. For a true cleanup to take place, we must stem the flow as well as clean up the mess.

Uncovering the plastics’ sources is a major step in preventing more of it from polluting our oceans, and a new study released in September by the Ocean Conservancy and McKinsey Center for Business and Environment seeks to do just that, as well as outline strategies for stopping the flow.

Although the report outlines many sources and causes of plastic debris, the most surprising finding is that the five countries mentioned above are responsible for such a high proportion of the problem. While historically these nations have not been major plastic consumers compared to western nations, plastic use has steadily grown as prosperity has risen. The awareness of the need to discard of or recycle plastic properly, however, has not risen with it. Existing collection systems also may not be in place or may not be functioning properly.

Another interesting, if not entirely surprising, finding in the report is that plastic of low value is more likely to be discarded, and thus find its way to the oceans. This points to the value of adding a fee to plastic products, which is then repaid when the used product is delivered to a collection system. In short, monetary incentives work.

The report suggests a number of other strategies that could reduce the amount of new plastic entering our oceans each year by as much as 65 percent.

Ensuring that collection systems don’t “leak,” that is, that collection systems are easy to find and use (to discourage illegal dumping) and that plastic garbage cannot accidentally leave the collection site and make its way into nearby waterways. Open landfills are examples of potentially leaking collection systems.

Putting waste-collection systems into place and improving on the ones that are already in place to ensure that plastic waste is collected and not discarded.

Recycling and upcycling plastic waste by either using it in its original form or close to it (recycling), or by turning the plastic waste into other, more valuable products to increase monetary incentives (upcycling). An example of the latter is plastic-to-fuel programs.

While the report is sobering, it’s clear that the problem is addressable if investments, both domestic and international, are made to ensure that these and other necessary initiatives are put into place in these developing nations to protect our marine environment.